EPHEDRINE SULFATE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for EPHEDRINE SULFATE (EPHEDRINE SULFATE).
Ephedrine sulfate is a sympathomimetic amine that directly stimulates alpha- and beta-adrenergic receptors and indirectly stimulates norepinephrine release from sympathetic neurons, leading to vasoconstriction, bronchodilation, and increased heart rate and contractility.
| Metabolism | Ephedrine is metabolized primarily by oxidative deamination via monoamine oxidase (MAO) and also by N-demethylation via CYP450 isoenzymes, though specific CYP enzymes are not well characterized. It has a half-life of 3–6 hours. |
| Excretion | Renal excretion of unchanged drug (60-70%) and minor metabolites; small amount biliary; pH-dependent; acidic urine enhances elimination. |
| Half-life | Terminal elimination half-life 3-6 hours in adults with normal renal function; prolonged in renal impairment or alkaline urine. |
| Protein binding | ~20-30% bound, primarily to albumin. |
| Volume of Distribution | ~2-3 L/kg; indicates extensive tissue distribution; crosses blood-brain barrier. |
| Bioavailability | Oral: ~85% (first-pass metabolism minimal); IM/SC: nearly 100%. |
| Onset of Action | IV: <1 minute; IM: 1-2 minutes; SC: 2-5 minutes; Oral: 15-30 minutes. |
| Duration of Action | IV: ~1 hour; IM: 1-2 hours; SC: 1-2 hours; Oral: 3-6 hours; tachyphylaxis may occur with repeated dosing. |
50 mg orally every 3-4 hours as needed; 25-50 mg intramuscularly or subcutaneously every 3-4 hours; 5-25 mg intravenously slowly every 5-10 minutes as needed, not to exceed 150 mg in 24 hours.
| Dosage form | SOLUTION |
| Renal impairment | GFR 10-50 mL/min: administer 75% of normal dose every 6 hours. GFR <10 mL/min: administer 50% of normal dose every 6 hours. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use or use with extreme caution, reduce dose by 75%. |
| Pediatric use | Oral: 3 mg/kg/day divided every 4-6 hours. Parenteral: 0.2-0.3 mg/kg/dose intramuscularly or subcutaneously every 4-6 hours; intravenous: 0.05-0.2 mg/kg/dose every 5-10 minutes as needed. |
| Geriatric use | Initiate at lower doses (e.g., 25 mg orally every 4-6 hours) due to increased sensitivity and risk of CNS stimulation and cardiovascular effects; monitor blood pressure and heart rate closely. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for EPHEDRINE SULFATE (EPHEDRINE SULFATE).
| Breastfeeding | Ephedrine is excreted into breast milk in small amounts. The milk-to-plasma ratio is approximately 2.5. At therapeutic doses, it is unlikely to cause adverse effects in the infant, but irritability and disturbed sleep have been reported. Caution is advised. |
| Teratogenic Risk | Ephedrine sulfate crosses the placenta. Use in the first trimester is associated with a small increased risk of gastroschisis. In the second and third trimesters, it may cause fetal tachycardia and uterine artery vasoconstriction, potentially leading to reduced uteroplacental blood flow. Animal studies have shown embryotoxicity at high doses. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to ephedrine or other sympathomimetics","Severe hypertension or coronary artery disease","Concurrent use with MAO inhibitors (MAOIs)","Narrow-angle glaucoma","Pheochromocytoma","Hypertrophic obstructive cardiomyopathy"]
| Precautions | ["Cardiovascular effects: hypertension, tachycardia, arrhythmias","Central nervous system stimulation: anxiety, insomnia, tremor","Tachyphylaxis with repeated use","Exacerbation of narrow-angle glaucoma","Use in patients with cardiovascular disease, hyperthyroidism, diabetes, or prostatic hypertrophy requires caution"] |
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| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and fetal heart rate continuously during intravenous use. Assess for signs of uterine hyperstimulation or fetal distress. In chronic use, monitor fetal growth and amniotic fluid volume. |
| Fertility Effects | Ephedrine may impair fertility in women by altering tubal motility and uterine contractility. In males, high doses have been associated with reduced sperm count and motility in animal studies. Clinical significance in humans is unclear. |